1. Field of the Invention
The present invention relates to a magnetic toner for an MICR printer, which is sometimes called "a toner for magnetic character recognition printing" or simply "a MICR toner", containing a binder resin and a magnetic powder, more particularly to a magnetic toner for an MICR printer having excellent properties in the printing density, the readability, the dispersibility, and the durability.
2. Description of the Related Arts
Recently identification marks called fonts are printed on checks, valuable securities, invoices, tickets and so on, in order to prevent counterfeit or alteration of these. This counterfeit-preventing method using these identification marks is called generally MICR (Magnetic Ink Character Recognition) system, with the toner for printing the fonts being called MICR toner, both of which are disclosed e.g. in Japan Patent Laid-open Pub. Nos. Hei 2-134648, and Hei 5-80582, and U.S. Pat. No. 5,034,298. Conventional MICR toner, however, had the problem that reading errors occurred frequently.
Hence in Japan Patent Laid-open Pub. Nos. Hei 4-358164, Hei 4-358165 and Hei 7-77829 is disclosed MICR toner using two kinds of magnetic powder, whose residual magnetization is controlled within 4.0-7.0 emu/g. The toner, however, had the following problems:
1) reading errors still occurred frequently, PA1 2) it was necessary to enhance image density, PA1 3) durability was low, and PA1 4) dispersibility of the magnetic powder included was low.